shift fork help

how do I know if my shift fork is bent...



1. What is it?



2. Where is it?



3. How do I know if it's bent.



My shifter was slipping out of gear when I would try and take off. What I found was that the little pin on top of the shift drum came out in the oil before I even split the cases.



Would that cause my problem?... I would think it would, personally. The the shift drum wouldn't be seated correctly right?



i am also installing the Kawasaki drum, and it has two holes for the pin. Do I need another one?



Thanks!